"到那时"怎么说

by then
by that time
until then
till then
明年圣诞结婚吧, 因为到那时你已经拿到硕士学位了。
Be married next Christmas, for you will have got your master's degree by then.
到那时她在这里就工作了三十年了。
By that time she would have been working here for thirty years.

at that time

by that time
by then
都可以

一楼的不对 是在那时的意思
二楼的对了几个 但是没文采
三楼对一个
bu the time then 比较好一点

at that time